Furnace-grate.



No. 806,422. PATENTED DBO. 5, 1905.

J. J. MERRILL.

FURNACE GR-ATE. APPLICATION FILED JULY:21 ,1904.

4 SHEBTS-SHBET 1.

No.806,422. PATENTED DEG.5,1905. J. J. MERRILL.

I FURNACE GRATE APPLICATION FILED JULY21,1904.

4 SHEETS-SHEET 2.

2: 19 IZI 7/04 7/111 No.806, 422. v'PAL FNTBD'mac.5,1905-, m. MERRILL.

FURNACE GRATE.

APPLIOATION FILED JULY 21,1904.

4 SHEETS-$33111 3,

YPATBNTED DEC. 5, 1905;

f1 SHEETS HEET 4.

J. J. MERRILL;

. FURNA'GB GRATE'. APPLICATION FILED JULY 21, 1904 UNITED AT S,

P T NT OFFICE.

' Specification of Letters Batent.

Patented Dec. 5, 1905.

Applicaticn filed July 21, 1904. Serial n. 217,532.

'To all whom it may concern:-

Be it known that-I, JOSEPH J. MERRILL, a

citizen of the United States, and a resident; of Ohicago,.in thecounty of Cook and State ,of Illinois, have invented certain. new and useful Improvements in FurnaceGrates;. and

I do hereby declare that the following is a; full, clear, and exact description thereof,ref-. erence being bad to the accompanying drawings, and to the letters of reference markedf thereon, which form a part of this specificai tion.

furnace-grates of the kind known generally as endless travelinggrates, or those in'which the grate-bars on which the fuel is supported move or travel inwardly from the feed-open-;

.ing of the furnace toward the interior thereof and afford support for the layer of fuel, which is continuously fed to the forward or; outer end of the grate and is moved inwardly by and upon the sameduring progressof' combustion v The inventlon cons1sts1n the matters hereinafter described, and pointed out in the appended claims.

grate embodying my invention.

2 2 of Fig. 1.

bar sections in elevation.

As illustrated in said drawings, A A indicate the side walls of the furnace; B, the bridgewall thereof; 0, the ash-pit; D, the feed-hopper at the front of the furnace; E: the fire-arch located over the front partof the fire-box; F, the front header of a water-tube boiler-which is located over said fire-arch,

and ff twoof the water-tubes in said boiler. The grate illustrated as embodying my in- .vention embraces a plurality of guide-bars vGr G of continuous ringor loop formand transversely arranged grate bar sections, 1

. which move or travel on said guide-bars and which are disconnected or unattached 'toeach other, but are in contact withieachlother,

so as to form a continuous loop or ring the upper part or lap of which constitutes the fuel-supporting part of the grate. Each grate-bar section according to the details of construction illustrated consists of two parallel supporting erods H H, which extend transversely of the furnace between the said guide-bars, and grate-bars I I, which extend longitudinally of the furnace and which extend between and are attached to said rods H H. Said grate-bars'I are spaced upon the I V r i t supporting-bars H 'H at regular intervals Th1s inventionirelates to Improvements 1n;

along thelength of the same' Each gratebar I consists'of a vertically-arranged web portion 1 having at its upper edge a plurality of laterally-extending fingers i, which are arranged transversely of the furnace and the upper edges of which constitute the fuel-supporting surface of the grate. The supporting-rods H are shown as engaged with grate-bars I by being inserted through aperjturesin the webs i of said grate-bars, said supporting-bars H H being preferably made of round or cylindric rods and the said webs c of the grate-bars being provided with thick- 'ened partsor hubs through which said bars In the accompanying drawings, Figure 1 is: a view in central longitudinal vertical sectioni of a steamboiler furnace provided with a Fig. 2 is a view thereof in cross-section, taken upon line Fig. 3 is a'detail section taken f upon line 3 3 of Fig. 1 with parts of the grate, omitted. Fig. 4 is a perspective view of the supporting-frame of the grate separate from i the other parts. Fig. 5 is an enlarged detail i section through the upper end of the grate. Fig. 6 is an enlarged detail section taken transversely through the supporting-frame on line 6 6 of Fig. 5, showing two of the grate:

extend, as clearly shown in the .drawings.

allel supporting-bars H H and the grate-bars I, which are attached to and connect-said supporting-bars, as above described, are engaged at their ends with the guide-bars G by having I said guide bars. Said guide-bars GG are arranged in vertical planes parallel with each other and embrace upper and lower straight parts joined at their ends by curved connect- The grate-bar sections, consistin of the par- IOG ing-portions. As preferably constructed said upper and lower parts of the guide-bars are parallel with each other and are joined at their ends by semicircular curved portions, as clearly seen in the drawings.

Any desired number of. the guide-bars G,-

with associated intermediate grate bar sections, may be employed; but in the particular construction illustrated four of said guidebars are used in connection with threesets of grate; These grate bar sections, as

' bar sections.

he'reinbefore stated, are not pivotally joined' or connected with each other, as in chain grates heretofore used, but the sections are arranged on the gulde-bars 1n contact with each other.

i In the particular construction shown the ends of the webs 71 of the individual link-bars are arranged to meet end to end or in abutting relation, said webs having at their ends bearing-surfaces d which are convexly curved,

so that they will remain in contact with eachother during the movement of the sections around the curved parts of the guide-bars G at the front and rear. ends of the grate.

Provision is made for driving the grate-bar sections or moving them continuously in an inward direction on the upper parts of the guide-bars and in an outward direction on the lower parts of said guide-bars, consisting of a rotative driving-shaft J, arranged concentrically with the forward curved ends of the guidebars G and provided with sprocketwheels K, of which preferably two are used for each set of grate-bar sections and the teeth or spurs of which are adapted to engage the supporting-bars H of the grate-bar sections as the sprocket-wheels are turned, so as to move or carry the grate-bar sections upwardly around the curved parts of the guide-bars and to deliver them to the upper parts of said guidebars. As the grate-bar sections are thus forced or carried one by one into the forward ends of the upper guide-bars the sections preceding them are pushed or thrust rearwardly, and thereby caused to travel continuously inward along said upper parts of the guide-bars. When the grate-bar sections reach the rear ends of the guide-bars, they will be forced around the curved connecting portions of the guide-bars therelocated and thence forwardly around the lower parts of the guide-bars, so that the rearward pressure imparted to the upper line of the sections by the sprocketwheels K K serves to move the entire series of bars continuously in a path determined by the shape of the guide-bars. The grate herein shown is rearwardly and downwardly inclined, with its lower end near the level of the bottom of the furnace. Such inclined arrangement of the grate is not, however, necessary,

and it may be otherwise arranged, if desired or preferred.

As preferably constructed the several guidebars G G are joined to each other by means of transverse girders N N N, which extend between the upper and lower parts of the bars and are bolted to the upper and lower edges of the same. The girders N and N are attached at their ends to standards 0 O, which are joined at their lower ends by connectingbars 0 and are provided at such lower ends with supporting-rollers P P. Like rollers P are mounted on the ends of the rear girder N Said rollers P, P, and P. rest and are adapted to travel on rails P supported on ledges formed on the side walls of the furnace. A rigid grate-supporting frame is thus formed which may be moved in and out of the furnace on said track-rails P.

Any suitable driving or actuating device may be employed for giving rotary motion to the driving-shaft J, that herein shown consisting of a horizontally-disposed worm L, mounted in a bracket Z, attached to one of the front standards O and adapted to engage a spur-wheel M on the end of the shaft J. The shaft of the worm-wheel L is provided with a rigidly-attached gear-wheel L, by which motion may be given to the said worm L.

Attached to and extending between the guide-bars G G at the rear end of the grate are curved plates Q Q, which extend along the inner edges of said guide-bars from the upper to the lower margin of the girder N In front of said girder N are located similar flat plates Q Q, which are also secured to and extend between said guide-bars adjacent to and forward of their upper and lower margins of said girder N the said plates Q and Q being likewise attached to the inner edges of said guide-bars. Said plates Q, Q, and Q serve to prevent ashes dropping through or between the grate-bar sections at the rear part of the grate upon the upper surfaces of the lower grate-bars when said grate-bar sections are separated from each other as they begin to move around the curved parts of the guidebars at such rear end of the grate. Such plates also serve to prevent the upward passage of air through the grate-bars at the extreme rear end of the grate.

As a means of controlling the upward passage of air through the rear part of the grate I have shown in Fig. 1 damper-plates R R R R as hinged to the lower surfaces of the upper parts of the guide-bars G in such manner that when opened their free edges may be dropped toward or upon the lower parts of said guide-bars and when elevated the free edge of each metal plate will meet the upper or hinged edge of the one in advance of it. The rearmost damper-plate R is shown as having its pivot located adjacent to the front edge of the stationary plate Q, and said plate is shown in said Fig. 1 as elevated or closed with its rear edge in contact, or nearly so, with the pivoted edge of the plate R, while the other plates R, R and R are shown as in their lowermost or open position.

By raising or lowering one or more of the damper-plates described air may be admitted to the layer of fuel resting on the grate near to or farther from the rear end of the grate, as required, according to the condition under which the furnace is operating. It is well understood that when combustion of the layer of fuel on the grate takes place so rapidly that the fuel is entirely or largely consumed before it reaches the rear end of the grate and the latter is covered by a thin layer of cinders and ashes only then it is desirable that the airsupply to that part of the grate should be IIO shut loflr, as otherwise a large portion of the 1 air would pass through such thin layer ofcin .ders and ashes, and the air-supply to the burning fuel would be'correspondingly lessened.

S indicates a damper-plate which is pivotally. supported at its .upper margin at a point near the lower lap .of the grate adjacent to I the rear end of the furnace and adapted. to exf V tend downwardly into contact with the bottom .be removed from the rear ofthe ash-pit. Said damper .S is shown as provided with .an actuating-rod S, attached at its lower 'edge and extending to the front .of the furnace, by which it may .be moved or E actuated Said damper-plate S serves to pre- 1 vent the. passage of air from the ash-pit around the rear .end of the grate and is pivot:

ally supported, as shown, :inorder that its free end may be lifted to'permit the ashes to part of the ash-pit behind the same. v .T indicates a water :cooled bridgepiece which extends along the front margin of the bridge-wall B in contact with the latter and just above the rear end of the grate and which serves to prevent the passage of air upwardly around the .rearlend of thegrate and I forwardly over the latter.

Said bridge-piece is arranged w1th its bottom surface at a distance above the grate-bar sections suflicient only to permit the passage beneath it of the layer of clinkers and ashes from the burnedout fuel and is preferably made in the form of a metal shell provided with water supply and return pipes, the ends of which are indicated byt t in Fig. 1, this construction being employed to enablethe bridge-piece to withstand the intense heat to which it is subjected.

U indicates a sliding fuel-door located over the feedopening of the furnace with its lower edge a short distance above the fuel-supporting surface of the grate and which ismade layer. Said door U is shown as consisting of adjustable to control the thickness of the this construction being employed to facilitate the inward travel or feed of the layer of fuel on said fuel-supporting surface. In connection with the grate, which is thus inclined, I provide upon the side walls of the furnace inwardly-projecting joint-plates V, which are inclined to correspond with the inclination of the upper parts of the guide-bars G and which extend over and overlap the outer margins of the upper surfaces of said guide-bars. Said joint-plates V are preferably stiffened by vertical flanges and. have outwardly-extending parts which are embedded in the masonry side walls .A A of the furnace.

By the employment of the inwardly-extending plate-joints V V, arranged as described, tight joints .may be maintained between the exterior guide-bars and the side walls of the furnace, it being manifest that when the grateframe as a whole is thrust into the furnace by reason of the inclination of said bars and of the upper surfaces of exterior guide-bars the latter maybe brought into close contact with the lower surfaces of' said plates V V. The presence of any spaces or openings'for the upward passage of air around the sides of the grate or between the side walls of the furnaceand ends of the grate-bar sections is thus avoided, it being, of .course, understood, as clearly seen in Fig. 2, that the external grate. bars .of said sections are located close to the external guidebars Gr Gr, so that the out.-

wardly-extending fingers on .said grate-bars extend or project over the said guide-bars and come close to the inner margins of said plates In order to enable the several grate-bar sec tions to beseparately disconnected from and engaged with the guide-bars Gr, said guide' bars, as shown in the drawings Figs. 4, 5, and 6, are provided near their forward ends in the upper flanges thereof with notches g of sufficient width to permit the passage therethrough of the rollers h on the supportingrods H H of said grate bar sections. The presence of said notches g enables the gratebars to be introduced into their places within or between the guide-bars after the guidebars have been joined or assembled to form the frame shown in Fig. 4 and to be removed from theirengagement with said guide-bars at any time without taking apart or separating the parts of said frame. The separate removal of the grate-bar sections without disturbing other parts of the apparatus is desirable for the purpose of repairs or replacing parts, it being obvious that if any of the grate-bars become injured by excessive heat or burned out the section to which it belongs may be readily removed from its place in the guide-bars, the separate grate-bars removed from the supporting-rods, new grate-bars introduced where necessary, and the repaired section readily and quickly introduced into its place in the guides. 1

I claim as my invention- 1. An endless traveling grate comprising transversely-arranged grate-bar sections which are disconnected or separate from'each other, each grate-bar section consisting of two parallel supporting-rods and grate-bars which extend between and are attached to said rods,

and guide-bars for thesaid sections provided with guide-grooves with which the ends of said rods are engaged.

2. An endless traveling grate comprising a plurality oftransversely-arranged gratesupporting-rods and a plurality of grate-bars which extend between and are attached to the said rods, guide-bars of loop form for the said sections provided with lateral guide-grooves, and rollers mounted on the ends of said rods and engaging the said guide-grooves.

3. An endless traveling grate comprising a plurality of transversely-arranged gratebar sections which are disconnected or separate from each other, a plurality of guide-bars with which the ends of said sections are engaged, said bars eachconsisting of straight parallel upper and lower parts joined at their ends by curved portions and transverse girders extending between the upper and lower parallel parts of said bars and attached at their upper and lower margins to the same, said guide-bars and girders constituting a rigid supporting-frame for the grate.

4. An endless traveling grate comprising a plurality of transversely-arranged grate- I sections which are disconnected or separate from each other, guide-barsprovided with grooves for engagement with projections on the ends of the sections, said guide-bars each section embracing two supporting-rods and a plurality of longitudinally arranged gratebars mounted side by side on said rods, the grate-bars of each of the sections being adapted for endwise contact with corresponding grate-bars of other sections.

In testimony that I claim the foregoing as my invention 1 aflix my signature, in presence of two witnesses, this 18th day of July, A. D.

JOSEPH J. MERRILL.

Witnesses:

O. CLARENCE PooLE, GERTRUDE BRYCE. 

